Incandescent lamp



Sept. 27, 1938. w. o. LANGILLE INCANDESCENT LAMP Filed May 7, 1937 M nm. m.

Patented Sept. ,27, 193g mcmnscnm'rnm v Wilfred Langille, Chester, N. Lallignor to The Singer Manufacturing -Coinpany, Elizabeth. N. J., a corporation of New Jersey appncauonlmy '1, 1937,311 No. 141,193

s claims.'l (o1. 11s-cz) This invention relates to incandescent lamps and particularly to lamps of that type which are `held in their supporting sockets by so-called bayonet joints.

A lamp of this type is usually formed on its base with one or more lead or solder contacts connected with the lamp lament and each adapted to be engaged by a spring-pressed plunger-pin carried by the lamp socket and connected with a source of electric current. It has been found that when lamps of this nature are usedin places where they are subjected 'to extreme vibrations, such for-example, as on high speed sewing machines, the vibrations cause the spring-plungers to produce a series of hammer blows on the contacts, with the result that the contacts are indented and consequently the electrical connection between the 'plungers and the contacts is impaired. This causes a makeand-break of the electric circuit and thereby effects arcing between the plunger and the Llead or solder contact which results in Athe melting and consequently th destruction of the contact. Thus, in such installations, two -conditions obtain each of which tends to destroy the lead contact; rst, the repeated blows of the plungers on the 'contacts which impairs the electrical connection between the two, and second, the arcing which melts the contacts.

In actual practice it has been found, that lamps of this nature, when used, for example on high speed sewing machines, cease to function long before the lamp lament has burned out. Attempts heretofore have been made to overcome this condition by endeavor-ing to reduce the vibration of the lamp socket. To that end, numerous vibration dampening supports have been proposed for such lamps, but none of them has been entirely successful in overcoming the diftirely obviated.

These objects have been attained by providing on th lamp-base one or more imperforate wearresisting metallic contacts which vwill effectively resist both the hammering eiect of the plungerpin and any arcing which may result due to relative movement between the plunger-pin and the contact.

With the above and other objects in view, as

will hereinafter appear, the invention comprises the method of manufacture, and the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawing which illustrates a preferred embodiment of the invention, and one method which may be employed in producing the same.

In the drawing. Fig. 1 is a perspective view of an incandescent lamp embodying the present invention.

Fig. 2 is a longitudinal sectional view, partly in elevation, of a lamp bulb showing the incandescent filament and lead-in wires therein.

Fig. 3 is a longitudinal sectional view of a lamp-base sleeve showing the pins which constitute a portion of a bayonet joint adapted to hold the lamp in its socket.

Fig. 4 is a sectional view of two eyelets later to be described.

Fig. 5 illustrates a section of the lamp-base sleeve and a closure therefonof insulating material in which the eyelets are embedded.

Fig. 6 is alongitudinal sectional view showing the lamp-base sleeve of Figure 5 cemented to that end of the lamp bulb containing the lead-in wires.

Fig. 7 is a perspective view of two imperforate metallic contact disks later to be described.

Fig. 8 is a view similar to Fig. 6 but showing the lead-in wires stretched tight, trimmed and soldered in the eyelets.

Fig. 9 is a fragmentary sectional view somewhat similar to Fig. 8 but showing the two imperforate metallic contact disks of Fig. 7- secured to the eyelets.

Fig. 10 is a longitudinal sectional view of a bayonet-type lamp socket and a portion of the present improved lamp inserted therein, with the contact disks of the lamp cooperating with the spring-pressed plungers of the socket.

Fig. 11 is a side elevation of a modified form of contact disk.

Referring more specically to the drawing the invention is disclosed as embodied in an incandescent lamp comprising an evacuated or gasiilled glass bulb i, lead-ln wires 2 extending therein and supporting a conventional incandescent filament 3. Surrounding the base of the bulb, and secured thereto, as by cement 4, is a metal sleeve 5 which carries oppositely extending radial pins 6 adapted to cooperate with notches 1 in a lamp-socket (see Fig. 10) to maintain the lamp within the socket. The pins 6 and notches 1 constitute a conventional bayonet" joint common to this type of lamp.

Within one end of the sleeve 5 is secured an insulating element 8, preferably of glass, in which are secured, as by moulding or otherwise, one or more metal eyelets 9. These eyelets are formed with substantially dat annular outer surfaces indicated at 9*. A v

It may be noted here that the present invention is adaptable. to both single contact lamps and multiple contact lamps. The lamp shown in the drawing is of the multiple contact type in which each-lead-in wire is connected with a contact button adapted to be engaged by a springplungerin the lamp socket, as distinguished from the single contact type in which one o! the leadin wires is grounded on the sleeve about the base of the lamp and the sleeve is suitably connected with the electric'circuit.

The lead-in wires 2 are secured Withinthe eyelets 9 and electrically connected thereto 4by solder I Il. As shown most clearly in Fig. 9 imperforate sheet metal contact disks II are `secured to the ilat outer surfaces 9 of the eyelets 9 and electrically connected with the lead-in wires 2. 'I'he disks II may be made of any suitable metal which is suillciently hard to resist the vimpact oi the plunger-pins of the lamp socket and which has a melting point sufficiently high to be unaiected by any arcing which might take place between the pin and the disk due to vibration. Commercial brass has been found l therefore transmit the necessary current to the lamp.

If desired, the contact disks II may be formed with convex outer surfaces as shown at IIX in Fig. 11.

As hereinbefore stated. this invention also provides an improved method of manufacturing lamps of this nature. This method comprises the various steps now to be described. Having prepared the evacuated or gas-lled lamp,` bulb I shown in Fig. 2, including the lead-in wires 2 and the illament 3, and having provided the sleeve 5, eyelets 9, and disks II, the parts are ready for assembly. First, the insulating element 8 is placed Within the sleeve 5 and the eyelets 9 are secured therein. This may be done by properly'positioning the eyelets relative to the sleeve 5 and then moulding the insulating material within the sleeve and about the eyelets 9 and the inner ends of the pins 6 as 'shown in Fig. 5. Next, thebase, comprising the sleeve 5 with the insulation therein, is placed over the end of the bulb containing the lead-in wires and the wires are threaded through the eyelets as shown in Fig. 6. The bulb is then secured in the sleeve, asby cement 4. 'I'he next step in the course of assembling consists in stretching or straightening the lead-in wires, trimming them oiI flush with the outer surfaces of the eyelets and securing them inthe eyelets as by lling the eyelet with molten solder as shown in Fig. 8. These taut wires may assist yin holding the base and the bulb together.

The nal step consists in Vsoldering to the outer ends 9'* of the eyelets, and in electrical contact with the lead-in wires 2, the imperforate hard metal disks II as shown in' Fig. 9. This may be done by first tinning one side of the disks alarmas v ll,fplacing the tinned side on the eyelets I9 and vibrations.

Insofar as I am aware, no one heretofore has provided a lamp of this type having imperforaie hard metal contact plates for receiving the thrust of the spring-pressed plunger-pins of the lamp socket. Neither has any one, so far as .I know, disclosed a method of manufacturing lamps which permits imperiorate metal plates to be secured to the lamp in electrical contact with the lead-in wires after the lamp has been otherwise completed. Certainlamps heretofore have been constructed with relatively hard metal contacts but in each of those lamps, in which the lead-in wires are taut and aid in securing the base to the'bulb, the metal contact has been formed with a perforation through which the lead-in wire is drawn taut after the contact plate has been secured to the lamp, the wire thereafter being soldered to the plate at the outside thereof.

Having thus set forth the nature of the invention what I claim herein isz- 1. An incandescent lamp comprising a base consisting of a sleeve, an insulating element substantially closing one end of said sleeve and an open-ended eyelet secured within said insulating element, said eyelet having a substantially at annular outer surface substantially flush with the outer surface of said insulating element; a bulb secured within said base; a filament within said bulb; a plurality of lead-in wires connected with said lament, one of said wires being elec- 2. An electric lamp comprising a glass bulb4 having a neck, a lamp-filament within said bulb, lead-in Wires extending through said neck into said bulb and connected to said filament, a lampbase sleeve secured to said neck, an insulating head within the contact end of said sleeve, a solder-containing lead-in terminal eyelet anchored in said insulating head, one of said leadin wires being embedded in the solder in said eyelet, and a wear-resisting contact disk of metal harder than the solder in said eyelet soldered to and covering the outer end of said solder-containing eyelet.

` 3. An electric lamp comprising a glass bulb having a neck, a lamp-filament withinsaid bulb, lead-in wires extending through said neck into said bulb and connected to said filament, a lampbase secured to said neck, an insulating head at thev contact end of said lamp-base, a solderfilled lead-in terminal eyelet, having a flaring solder-receiving mouth and a reduced neck, anchored in said insulating head, one of said leadin wires being embedded in the solder in said eyelet, and a pre-formed contact disk of wear- O. LANGILLE. 

